Fly, Daddy, Fly (2006)

A salary man finds that his daughter has been assaulted by high school boys, including the school boxing star from an important government family, Tae-wook. Desperate to protect his daughter, he plans to stab Tae-wook on the way to school. He is stopped by a student, Seung-suk, who agrees to train him to fight so that he can face Tae-wook honorably. The movie is based on Kaneshiro Kazuki's novel "Fly, Daddy, Fly", which has a similar Japanese movie based on it as well.